Capsule for storage, mixing and dispensing materials

ABSTRACT

The present invention relates to a capsule for storage, mixing and dispensing of materials, preferably dental materials like glass ionomer cement. The capsule comprises a capsule body member that provides a main chamber and comprises a dispensing opening, a receptacle providing an auxiliary chamber, said receptacle being accommodated in said capsule body member, and an applicator member being slideably accommodated in said capsule body member.

PRIORITY CLAIM

This application claims priority from European Patent Application No. 04005801.8, filed Mar. 11, 2004.

FIELD OF THE INVENTION

The present invention relates to a capsule for storage, mixing and dispensing of materials, preferably dental materials, most preferably glass ionomer cements. In particular, the present invention relates to a capsule for storage, mixing and dispensing materials which preferably consist of a plurality of, i.e., two or more components.

BACKGROUND OF THE INVENTION

Mixing capsules which are filled with the components in separate chambers by the manufacturer are used to produce mixtures of two or more components. The components are brought into communication and mixed with one another by the user, for example by destroying a wall separating the chamber.

Mixing capsules for the production of dental materials which are often mixed from a pulverulent component and a liquid component, the mixing procedure usually taking place in a shaker unit, are known in the dental sector. The completely mixed substance is then dispensed directly onto the working area, for example into a tooth cavity, through a dispensing spout formed integrally on the mixing capsule.

DE-A-36 35 574 discloses a mixing capsule intended for the production of jointing and sealing compounds. In an illustrative embodiment described in said document, an auxiliary chamber which is present in the dispensing piston is delimited, on the side facing the main chamber of the capsule, by a foil and, on the opposite side, by an auxiliary piston which is displaceably arranged in the dispensing piston. In the initial state of the mixing capsule, in addition to the second component, a mixer body is accommodated in the auxiliary chamber, which mixer body initially serves to destroy the foil by means of manual displacement of the auxiliary piston and then assists in the mixing procedure. To allow the reduction in volume which is necessary for displacement of the inner piston together with the mixer body, a gas cushion is provided in the mixing chamber.

In a further embodiment of the known mixing capsule, the mixing body is initially situated in the main chamber. In this case, the auxiliary chamber present in the piston is closed off from the main chamber by means of a cover and on its rear side by a bellows. As a result of manual pressure being applied to the bellows, the cover is pressed away from the piston, so that the two chambers are brought into communication for the purpose of activating the capsule.

In both cases, a dedicated working step which has to be carried out manually is required for activation of the capsule. Furthermore, a gas cushion is required in order to permit the reduction in volume which is required for removal of the cover.

In a multi-component mixing capsule for dental purposes which is known from DE-U-94 00 374, a first component is contained in a mixing chamber and a second, liquid component is contained in a foil bag which is arranged in an auxiliary chamber which is separated from the mixing chamber by a displaceable wall element. A cylindrical mixing body which is present in the mixing chamber is used to displace the wall element at the start of the mixing procedure and thus to compress the foil bag, so that the latter bursts open and releases the liquid component through a liquid passage which is present in the wall element.

U.S. 2003/0136799 discloses a mixing capsule that comprises a cartridge, a dispensing spout and a piston which is displaceably arranged in the cartridge, a sealed main chamber for receiving a first component, an auxiliary chamber which is provided in the piston and receives a second component, at least one freely movable body, and a separating device which separates the auxiliary chamber from the main chamber and through which the body can penetrate. The body is arranged in the main chamber when the separating device closed, and the auxiliary chamber and the body are designed in such a way that, during the dispensing operation, the body can pass into the auxiliary chamber as a displacement body.

SUMMARY OF THE INVENTION

The present invention provides an improved capsule for storage, mixing and dispensing of materials that does not require a separate mixing body.

The present invention provides a capsule for storage, mixing and dispensing of materials comprising a capsule body member providing a main chamber, and comprising a dispensing opening, a receptacle providing an auxiliary chamber, said receptacle being accommodated in said capsule body member, and an applicator member being slideably accommodated in said capsule body member. The main chamber and the auxiliary chamber are selectively connectable for fluid communication between said chambers upon activation of said capsule by said applicator member. The main chamber comprises a powder material, and the auxiliary chamber preferably comprises a liquid. The applicator and/or the receptacle are adapted such that the receptacle releases material contained in the auxiliary chamber under pressure created by that applicator member when a fluid connection exists between said chambers.

The inner wall of the capsule body member preferably comprises a stepped configuration forming a step in a plane perpendicular to the longitudinal axis of the capsule body member. Preferably, the step divides the interior of said capsule body member into a first part and a second part. The first part is located between the dispensing opening and the second part and has a smaller cross-sectional area than said second part, preferably a smaller diameter than the second part. The receptacle preferably rests on said step.

According to a preferred embodiment, the receptacle comprises an annular element and two film elements that are attached to the annular element at the two sides of the annular element in order to form said auxiliary chamber. Preferably, the inner diameter of the annular element equals the diameter of said first part of said capsule body member. It is also preferred that the two films are attached to said annular element in order to form a hermetically sealed chamber. According to a preferred embodiment, at least one film of said receptacle comprises an area of weakness in order to facilitate breaking of the film upon application of pressure.

The applicator member preferably comprises a piston element and a tubular element accommodating said piston element. The diameter of said piston element preferably equals the diameter of said first part of said capsule body member. Thus, the piston can slide through the annular ring of the receptacle into the first part of the capsule body member.

The applicator member further comprises a punching element, for example, a conical spike.

According to a preferred embodiment, the capsule further comprises a cannula member. Preferably, the cannula member is connected to said dispensing opening or is alternatively integrally formed with said capsule body member. The connected cannula member is preferably rotatable about its longitudinal axis in order to provide a dispensing valve.

The materials preferably comprise dental materials, more preferably glass ionomer cements or resin modified glass ionomer cements.

According to a preferred embodiment of the present invention, the film of the receptacle facing the piston member (i.e., the back-end film of the receptacle) is punched through upon movement of the piston member into the capsule body member. If the piston member is moved further into the capsule body member, the other film of the receptacle (i.e., the front-end film) will burst by hydraulic pressure, and the material, preferably liquid, contained in the auxiliary chamber is pressed into the main chamber. According to a preferred embodiment, at least the front-end film of the receptacle comprises an area of weakness that is formed, for example, by laser engraving, which facilitates breaking of the film along the weakened lines.

In a further preferred embodiment, the piston member comprises a puncture means, for example, a conical spike, as mentioned above. In this case, the back-end film of the receptacle is pierced by the spike but sealed again against the piston member because of the conical geometry of the spike. If the piston member is moved further into the capsule, the back-film will be completely punched through, and at the same time the front-end film of the receptacle is pierced. Due to the hydraulic pressure within the receptacle, the front-end film swells and thus allows liquid to pass through a gap between the spike and the pierced hole in the front end film.

The capsule according to the present invention eliminates the need for a separate activation device. This provides a simplified handling and time saving for the dentist.

Furthermore, the capsule according to the present invention is advantageous because correct activation of the capsule is visible for the dentist which reduces the risk for failures.

It is preferred that additional sealing features are provided separately or in combination at the rear end of the capsule. A first preferred additional sealing feature is formed by a sealing balloon which is attached to the rear end of the tubular element encasing the rear end of the piston element, thus additionally sealing the auxiliary chamber against the exterior of the capsule. The same effect is preferably achieved with a sealing hose that is attached to the rear end of the tubular element and to the rear end of the piston element. Thus, the sealing hose spans the gap between the rear end of the tubular element and the rear end of the piston element. A similar sealing hose is preferably used to provide an additional seal between the body member and the tubular element. This sealing hose spans the gap between the rear end of the body member and the rear end of the tubular element. Alternatively or in addition, another sealing balloon is attached to the rear end of the body member encasing the tubular element and the piston element, thus completely sealing the rear end of the capsule against its exterior. The same effect is achieved with a sealing hose that is attached to the rear end of the body member and to the rear end of the piston element. Thus, the sealing hose spans both the gap between the rear end of the body member and the rear end of the tubular element, and the gap between the rear end of the tubular element and the rear end of the piston element. It should be clear that it is not necessary to provide all of those additional sealing features at the same time. Preferably, at least one of these additional safety features is present.

Preferably, the capsule contains in its main chamber a first, preferably powdery, component of said material to be dispensed, and contains in its auxiliary chamber a second, preferably liquid, component of said material.

According to a second aspect, the present invention provides a kit, comprising at least one of the capsules of the present invention.

According to a third aspect, the present invention provides the use of the capsules of the present invention for mixing a material of two or more components.

The capsule of the present invention does not have conventional burst sachets that require huge burst forces and can therefore be activated without the use of an activator tool. Because the receptacle is formed of an annular element the receptacle can be easily adapted to different volumes by just changing the length of the element. While the maximum volume of burst sachets is limited by various factors that cannot easily be changed within one capsule design, the receptacle of the present capsule allows especially higher volumes to be achieved without major modifications of the capsule.

A further advantage related to the capsule of the present invention is that the entire capsule consists of four components only. This optimises manufacturing processes, and reduces manufacturing costs. In particular, the assembly lines for the assembly of the discharge cannula, a cannula holding cap, the sachets and the sachet holding clamp that are conventionally used can be eliminated completely. Furthermore, filling processes (powder and liquid) can be made in line with the assembly of the four parts.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is now described in more detail with reference to the accompanying drawings, in which

FIG. 1 shows a cross-sectional view of the capsule according to the present embodiment;

FIG. 2 shows the capsule of FIG. 1 with optional additional sealing features; and

FIG. 3 shows a cross-sectional view of the activated capsule according to the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 shows a capsule 100 according to a preferred embodiment of the present invention. Capsule 100 comprises a capsule body member 101 forming a main chamber 102. Capsule body member 101 comprises a dispensing opening 103. In the embodiment shown in FIG. 1, a cannula 104 is integrally formed with the capsule body member.

Capsule body member 101 comprises a stepped configuration so that a step 107 is formed between a first part 105 and a second part 106 of the capsule body member 101. The diameter of the first part 105 is smaller than the diameter of the second part 106. A receptacle comprising an annular member 110 and two films 111, 112 forms an auxiliary chamber 113. The receptacle is located within the capsule body member at step 107. As shown in FIG. 1, the inner diameter of annular element 110 is equal to the diameter of the first part 105 of the capsule body member 101.

Furthermore, capsule 100 of the embodiment shown in FIG. 1 comprises a piston element 120. Piston element 120 has a diameter that is equal to the inner diameter of the annular element 110 of the receptacle and the diameter of first part 105. Piston element 120 is slideably accommodated in a tubular element 121 that, in turn, is (at least in part) accommodated in the second part 106 of the capsule body member 101. Piston element 120 shown in FIG. 1 comprises a conical spike 123 in order to punch through the two films 111 and 112.

FIG. 1 also shows that tubular element 121 comprises an annular groove 122. Annular groove 122 may preferably accommodate a sealing element such as an O-ring.

It is preferred that additional sealing features are provided separately or in combination at the rear end of the capsule. These are shown in FIG. 2. A first preferred additional sealing feature is formed by a sealing balloon 131 which is attached to the rear end of the tubular element 121 encasing the rear end of the piston element 120, thus additionally sealing the auxiliary chamber 113 against the exterior of the capsule. The same effect is preferably achieved with a sealing hose 132 that is attached to the rear end of the tubular element 121 and to the rear end of the piston element 120. Thus, the sealing hose 132 spans the gap between the rear end of the tubular element 121 and the rear end of the piston element 120. A similar sealing hose 133 is preferably used to provide an additional seal between the body member 101 and the tubular element 121. This sealing hose 133 spans the gap between the rear end of the body member 101 and the rear end of the tubular element 121. Alternatively or in addition, another sealing balloon 130 is attached to the rear end of the body member 101 encasing the tubular element 121 and the piston element 120, thus completely sealing the rear end of the capsule against its exterior. The same effect is achieved with a sealing hose (not shown) that is attached to the rear end of the body member 101 and to the rear end of the piston element 120. Thus, the sealing hose spans both the gap between the rear end of the body member 101 and the rear end of the tubular element 121, and the gap between the rear end of the tubular element 121 and the rear end of the piston element 120. It should be clear that it is not necessary to provide all of those additional sealing features at the same time. FIG. 2 shows all such safety features at a single capsule just for ease of explanation. Preferably, at least one of these additional safety features is present.

FIG. 3 shows capsule 100 in its activated position with spike 123 being punched through the two films 111 and 112. Thus, the material, for example the liquid contained in auxiliary chamber 113 has already been pressed into main chamber 102. Main chamber 102 preferably contains a powder. The liquid is mixed with the powder and the resulting substance is dispensed through dispensing opening 103 and cannula 104.

List of Reference Signs

-   100 capsule -   101 capsule body member -   102 main chamber -   103 dispensing opening -   104 discharge cannula -   105 first part of capsule body member -   106 second part of capsule body member -   107 step -   110 annular member -   111 first film -   112 second film -   113 auxiliary chamber -   120 piston element -   121 tubular element -   122 annular groove -   123 spike -   130 sealing balloon -   131 sealing balloon -   132 sealing hose -   133 sealing hose 

1. Capsule for storage, mixing and dispensing of materials comprising: a capsule body member providing a main chamber, and comprising a dispensing opening at the front end of said capsule body member; a receptacle comprising an auxiliary chamber, said receptacle being accommodated in said capsule body member; and an applicator member for activating said capsule and for dispensing mixed materials; said applicator member being slideably accommodated in said capsule body member, said applicator member being provided at the rear end of the capsule body member; said main chamber and said auxiliary chamber being selectively connectable for fluid communication between said chambers upon activation of said capsule by said applicator member; said applicator member and/or said receptacle being adapted such that said receptacle releases material contained in the auxiliary chamber under pressure created by said applicator member.
 2. The capsule of claim 1, wherein the inner wall of said capsule body member comprises a stepped configuration forming a step in a plane perpendicular to the longitudinal axis of the capsule body member.
 3. The capsule of claim 2, wherein said step divides the interior of said capsule body member into a first part and a second part, said first part being located between said dispensing opening and said second part and having a smaller diameter than said second part.
 4. The capsule of claim 2, wherein said receptacle rests on said step.
 5. The capsule of claim 1, wherein said receptacle comprises an annular element and two film elements being attached to the annular element at the two sides of the annular element in order to form said auxiliary chamber.
 6. The capsule of claim 2, wherein said receptacle comprises an annular element and two film elements being attached to the annular element at the two sides of the annular element in order to form said auxiliary chamber.
 7. The capsule of claim 3, wherein said receptacle comprises an annular element and two film elements being attached to the annular element at the two sides of the annular element in order to form said auxiliary chamber.
 8. The capsule of claim 5, wherein the inner diameter of said annular element equals the diameter of said first part of said capsule body member.
 9. The capsule of claim 5, wherein said two films are attached to said annular element in order to form a hermetically sealed chamber.
 10. The capsule of claim 5, wherein at least one film of said receptacle comprises an area of weakness in order to facilitate breaking of the film upon application of pressure.
 11. The capsule of claim 1, wherein said applicator member comprises a piston element and a tubular element accommodating said piston element.
 12. The capsule of claim 11, wherein the diameter of said piston element equals the diameter of said first part of said capsule body member.
 13. The capsule of claim 1, said applicator member further comprising a punching element.
 14. The capsule of claim 13, said punching element being a conical spike.
 15. The capsule of claim 1, further comprising a cannula member.
 16. The capsule of claim 15, the cannula member being connected to said dispensing opening or being integrally formed with said capsule body member.
 17. The capsule of claim 16, said connected cannula member being rotatable in order to provide a dispensing valve.
 18. The capsule of claim 1, wherein said materials comprise dental materials.
 19. The capsule of claim 18, wherein said materials are glass ionomer cements or resin modified glass ionomer cements.
 20. The capsule of claim 1, wherein said main chamber contains a first, preferably powdery, component of said material, and said auxiliary chamber contains a second, preferably liquid, component of said material.
 21. A kit, comprising at least one of the capsules of claim
 1. 